There's a lot of cool chemistry involved in the eye adjusting to darkness and light. My favorite fun fact is that as you adjust to darkness, the spectrum of lig

There's a lot of cool chemistry involved in the eye adjusting to darkness and light. My favorite fun fact is that as you adjust to darkness, the spectrum of light your eye perceives becomes slightly blueshifted: http://en.wikipedia.org/wiki/Purkinje_effect http://en.wikipedia.org/wiki/Purkinje_effect